There is a long history of law enforcement not taking threats of violence seriously, when they come from white conservative groups.
The Secrete Service might. As far as I know they take all threats to the president as pretty serious. But that only helps the president, not the rest of us.
Primarily because if courts admit it's fallible, everyone convicted in part on bite evidence would need to be retried. Which would be a crazy amount of work. And people are lazy. Epically courts.